In order to remain competitive with increased competition from casting and the tendency to design away from forged parts due to costs, today's die block maker must offer die block quality equal to current quality at lower cost, or a better quality at equal or lower cost, in order to reduce the unit cost of parts produced. An average production run increase of only a few percent or a few thousand pieces will impact heavily on the unit cost. The typical rugged operating conditions to which products of this invention are subjected are well described in U.S. Pat. No. 3,929,423, the subject matter of which this invention constitutes an improvement upon. As there described, die blocks of the type to which this invention is directed are subjected to unusually severe operating conditions during normal use since, among other things, they are subjected to intermittent heating and cooling from temperatures of, for example, about 300.degree. F. to about 1100.degree. F. and more, heavy impact loads and severe abrasion. Under abnormal working conditions, which invariably occur from time to time in any operation, the die blocks may be subjected to prolonged exposure at high temperatures as where a high temperature workpiece becomes stuck in the dies, or where a large forging is not lifted from the lower cavity between blows. Concurrently with the aforesaid operating conditions the die blocks must be relatively easily machinable, mainly after final heat treatment.